One embodiment relates to an apparatus for adjustment of local magnetic strength in a magnetic device. A stage holds the magnetic device, and a sensor measures a magnetic field at locations above the magnetic device so as to generate magnetic field data. A computer system detects a non-uniformity in the magnetic field from the magnetic field data and determines a location and a duration for application of a pulsed laser beam to correct the non-uniformity. A laser device applies the pulsed laser beam at said location for said duration. Another embodiment relates to a method of adjusting local magnetic strength in a magnetic device. Another embodiment relates to a system for fine-tuning a magnet array with localized energy delivery. Other embodiments, aspects and features are also disclosed.